1. Field of the Invention
This invention is directed to wellbore coiled tubing connectors, to coiled tubing systems with such a connector, and to methods of their use.
2. Description of Related Art
Coiled tubing is used in many prior art systems instead of jointed pipe or jointed tubing wells, as drill pipe, production tubing, or casing, during well drilling or servicing operations, using either a drilling rig or a workover rig. Various kinds of downhole equipment tools, bottom hole assemblies, stabilizers, drill motors, and bits are attached to the end of coiled tubing.
Coiled tubing (e.g. of a relatively small diameter, e.g. approximately one inch) provides the maximum amount of tubing which can be mounted on a reel, but such small diameter coiled tubing: limits the flow of fluids; limits the amount of compression force that can be transmitted through the string of tubing in the well; limits the amount of tension that can be placed on the string of tubing; limits the amount of torque that the tubing can withstand; limits the type and weight of tools that may be used; and limits the length of tubing that may be used. Larger sizes of coiled tubing are also used in diameters ranging up to three and one-half inches and larger, but the use of such coiled tubing with small reels and associated handling apparatus may be difficult.
Typical prior art coiled tubing handling equipment includes a reel of coiled tubing mounted on a platform or vehicle, an injector to run the tubing into and out of the well, a gooseneck adjacent and/or permanently affixed to the injector for guiding the coiled tubing between the reel and the injector, a lifting device to support the injector and the gooseneck, a hydraulic power pack to provide power to the reel and the injector and to other hydraulic equipment, and surface equipment such as strippers and blow-out preventers to seal around the coiled tubing as it is run into and out of the well. A trailer or skid is used to transport the reel which may be of various sizes, depending upon the size of the coiled tubing to be reeled thereupon, and the length of coiled tubing to be carried. Repeated reeling and unreeling of coiled tubing on a reel increases tubing fatigue due to bending stresses.
Typically the injector is supported by the lifting device and the gooseneck includes a hydraulically powered boom or crane located at the rear of the coiled tubing trailer over the well. The hydraulically powered injector has drive chains with tubing grippers. The drive chains are hydraulically pressed against the tubing to grip the tubing and hydraulically driven sprockets drive the chains to run the tubing into or out of the well. The hydraulic power pack includes one or more engines driving one or more hydraulic pumps to power the reel, the crane, the injector, and other equipment. Other types of power equipment are also used.
A typical gooseneck has a curved guide member that receives tubing extending from the reel, uncoils the tubing from the reel, and guides the tubing between the drive chains of the injector. A plurality of rollers on the gooseneck support the tubing while the tubing is being guided by the gooseneck into the injector. Small radius bends found in certain goosenecks result in stress on the tubing.
In certain wellbore operations a relatively long tool, tools, or wellbore apparatuses must be connected to the end of the coiled tubing. Such an assembly is generally much stiffer than the coiled tubing and the positioning of such an assembly over a wellhead can result in stress on the coiled tubing which is greater than the typical bending and plastic deformation of the tubing during its passage through the gooseneck. Such stress can cause fatigue failure of the tubing.
There has long been a need for an efficient and effective coil tubing system which can include a relatively long, relatively stiff assembly at the end thereof whose use does not result in the application of severe stresses to the coiled tubing.
The present invention, in certain embodiments, discloses and teaches a coiled tubing holder that has gripping apparatus (e.g. but not limited to as in internal slip and roll-on connectors) at one end for selectively gripping an end of coiled tubing and a connector movably connected to or interconnected with the gripping apparatus. In one aspect the movable connector has an end formed or machined so that it can not only rotate about a longitudinal axis of the holder, but can also move laterally away from the longitudinal axis, in one aspect tracing a conical or partial conical path at the end of the holder. This freedom of movement inhibits the transmission of stress to the coiled tubing.
In one aspect the movable connector is initially rotatable with respect to a housing member. The gripping apparatus is connected at the top of the housing member. The housing member has one or more lower clutch recesses and the movable member has one or more top drive lugs sized for selective receipt in the clutch recesses. The housing member has an inner space up into which the movable connector moves when housing member is moved downwardly about the movable connector. As the housing member moves down, the drive lug(s) move into the clutch recess(es) locking the two members together so that rotation of the gripping apparatus and housing member rotates the movable connector and whatever tools or apparatuses are connected to and beneath the movable connector. Alternatively such a selectable driving connection is achieved with mating spline members on the movable connector and on the housing, the splines of the movable connector moving up into and between corresponding spline members of the housing.
In certain embodiments the movable connector (or a lower member secured thereto) is provided with wrench flats and a threaded end for threaded engagement with a tool, device, or wellbore apparatus. A suitable wrench is used on the wrench flats to threadedly connect the movable connector or lower member to the tool, etc.
In certain embodiments the housing member has one or more holes therethrough through which a set screw or bolt is used to releasably hold the movable member to the housing member. A hole or groove may be provided in the housing member for receiving a portion of the set screw or bolt.
The movable member disclosed herein may be used in any tool or apparatus to absorb bending stress. The movable member disclosed herein may be used with any known tubing connector, including, but not limited to internal slip and roll-on connectors.
It is, therefore, an object of at least certain preferred embodiments of the present invention to provide:
New, useful, unique, efficient, nonobvious coiled tubing connectors, coiled tubing systems with such a connector, and methods of their use;
Such connectors, systems, and methods which permit a tool, system device, or apparatus to have freedom of movement thereby reducing stress on the coiled tubing to which an intermediate connector is connected; and
Such connectors, systems and methods in which a movable connector initially moves with respect to a housing member but is selectively lockable thereto for rotation thereby and therewith.
Certain embodiments of this invention are not limited to any particular individual feature disclosed here, but include combinations of them distinguished from the prior art in their structures and functions. Features of the invention have been broadly described so that the detailed descriptions that follow may be better understood, and in order that the contributions of this invention to the arts may be better appreciated. There are, of course, additional aspects of the invention described below and which may be included in the subject matter of the claims to this invention. Those skilled in the art who have the benefit of this invention, its teachings, and suggestions will appreciate that the conceptions of this disclosure may be used as a creative basis for designing other structures, methods and systems for carrying out and practicing the present invention. The claims of this invention are to be read to include any legally equivalent devices or methods which do not depart from the spirit and scope of the present invention.
The present invention recognizes and addresses the previously-mentioned problems and long-felt needs and provides a solution to those problems and a satisfactory meeting of those needs in its various possible embodiments and equivalents thereof. To one skilled in this art who has the benefits of this invention""s realizations, teachings, disclosures, and suggestions, other purposes and advantages will be appreciated from the following description of preferred embodiments, given for the purpose of disclosure, when taken in conjunction with the accompanying drawings. The detail in these descriptions is not intended to thwart this patent""s object to claim this invention no matter how others may later disguise it by variations in form or additions of further improvements.